Shellfish Conflict in Baynes Sound: A Strategic Perspective

The shellfish aquaculture industry (SAI) has operated in Baynes Sound, British Columbia (BC) since the early 1900s. Recognizing the economic potential of the area, the industry has requested additional farming opportunities. However, Baynes Sound upland residents and many other stakeholders have expressed concerns that SAI activities are having a negative impact on the environment, quality of life, and other nonaquaculture resource uses in the area. In order to address these issues, the Action Plan was initiated by a BC government interagency project team in November 2001. To assist in assessing the strategic aspects of this conflict, the decision support system GMCR II is employed here to apply a new methodology, the graph model for conflict resolution, to systematically analyze the ongoing conflict over shellfish aquaculture development in Baynes Sound within a social, economic, and environmental framework. Valuable insights are procured to guide decision-makers toward sustainability of the shellfish industry.     

Grassland Management Activity Data: Current Sources and Future Needs

Estimates of potential and actual C sequestration require areal information about various types of management activities. Forest surveys, land use data, and agricultural statistics contribute information enabling calculation of the impacts of current and historical land management on C sequestration in biomass (in forests) or in soil (in agricultural systems). Unfortunately little information exists on the distribution of various management activities that can impact soil C content in grassland systems. Limited information of this type restricts our ability to carry out bottom-up estimates of the current C balance of grasslands or to assess the potential for grasslands to act as C sinks with changes in management. Here we review currently available information about grassland management, how that information could be related to information about the impacts of management on soil C stocks, information that may be available in the future, and needs that remain to be filled before in-depth assessments may be carried out. We also evaluate constraints induced by variability in information sources within and between countries.It is readily apparent that activity data for grassland management is collected less frequently and on a coarser scale than data for forest or agricultural inventories and that grassland activity data cannot be directly translated into IPCC-type factors as is done for IPCC inventories of agricultural soils. However, those management data that are available can serve to delineate broad-scale differences in management activities within regions in which soil C is likely to change in response to changes in management. This, coupled with the distinct possibility of more intensive surveys planned in the future, may enable more accurate assessments of grassland C dynamics with higher resolution both spatially and in the number management activities.     

Book reviews

What Time is This Place?

Kevin Lynch

The MIT Press, Cambridge and London, England 1972, VIII and 277 pp, $5.95.

Planning and Profit in the Urban Economy

T. A. Broadbent (1977)

London: Methuen & Co.

"Sociology in Planning: a redefinition"

G. McDougall, J. Foulsham and J. Porter.

S.I.P. Paper No. 3, 1977, 27pp. Price 50p. Published by the organisation of Sociologists in Polytechnics and Cognate Institutions.

"Urban Freight Transport: problems and some possible solutions"

Alan R. Boyland

Working Papjer No. 26, Oxford Polytechnic Department of Town Planning.

A Critique of Urban Modelling

R. A. Sayer

Progress in Planning Series, edited by D. Diamond and J. B. McLoughlin, Volume 6, Part 3.

The Communications Factor in Office Decentralisation

J. B. Goddard and D. Morris

Progress in Planning Series edited by D. Diamond and J. M. McLoughlin, Vol. 6, Part 1.

Spatial Population Analysis

P. H. Rees and A. G. Wilson

Arnold, London, 1977. £27.50.

The Design Guidance Survey

Llewelyn‐Davies, Weeks, Forestier‐Walker and Bor. London 1976.     

REDUCING THE RISK OF FISHERY RESOURCE DISASTERS: A BIOECONOMIC APPROACH TO SUSTAINABLE RESOURCE MANAGEMENT1

Abstract: Recognition is growing that fisheries must be both ecologically and commercially sustainable. The bioeconomic models proposed herein constitute an analytic framework capable of integrating the ethics and Societal values associated with fisheries preservation. Specifically, we focus on the normalized optimal (equilibrium) fish population, z*, a dimensionless variable representing biomass as a proportion of environmental capacity. We model z* as a function of (a) the dimensionless "bionomic growth ratio", γ, which is the ratio of the discount rate to the intrinsic population growth rate, and (b) the preservation coefficient, Ω, which is the ratio of the preservation value (a measure of Society's value for the stock) to price, assuming that the population growth rate and intrinsic growth rate are fixed. It is shown that increasing Ω significantly impacts z*, particularly for moderate values of γ (2 γ 4). Finally, stochastic population models are used to analyze the risk of a fish stock collapse due to harvesting pressures. The bioeconomic models and simulations herein described improve the accuracy and reliability of maximum sustainable yield management.     

Importance of indirect nitrous oxide emissions at the field, farm and catchment scale

Direct and indirect nitrous oxide (N₂O) emissions and leaching losses from an intensively managed grazed pasture in the Ythan catchment, Aberdeenshire, UK, were measured and compared over a 17-month period. Simultaneous measurements of farm-wide leaching losses of N₂O were also made and catchment-wide fluxes were estimated from existing N leaching data. The relative importance of direct and indirect N₂O fluxes at the field, farm and catchment scale was then assessed. At the field scale we found that direct N₂O emissions were low (1.2 kg N ha⁻¹ year⁻¹, 0.6% of N input) with indirect N₂O emissions via drainage waters comprising a significant proportion (25%) of total N₂O emissions. At the whole-farm scale, the N₂O-N emission factor (0.003) for leached NO₃-N (EF_5-g) was in line with the IPCC's recent downward revision. At the catchment scale, a direct N₂O flux of 1.9 kg N ha⁻¹ year⁻¹ and an indirect flux of 0.06 kg N₂O-N ha⁻¹ year⁻¹ were estimated. This study lends further support to the recent downward revision of the IPCC emission factor for N₂O arising from leached N in surface and ground waters (EF_5-g) and highlights the need for multiple point sampling to ensure that the importance of indirect N₂O losses via drainage waters is not misrepresented at the farm and catchment scales.     

Sustainable fishing gear: the case of modified circle hooks in a Costa Rican longline fishery

Our research aims to identify longline fishing gear modifications that can improve fishing selectivity and reduce incidental capture of non-target species. Catch rates and anatomical hook locations (AHL) were compared when using a 14/0 standard ??control?? circle hook with a 0° offset and an experimental ??appendage?? hook in a Costa Rican longline fishery. With the appendage, the maximum dimension of the appendage hook was increased by 10% and the minimum dimension of the hook by 19%. A total of 1,811 marine animals were captured during five fishing trips. By taxonomic groups, sea turtles represented the largest total catch (27%), followed by sharks (26%), rays (25%), mahimahi (Coryphaena hippurus) (12%), and tunas and billfish (10%). Non-target and discard species, such as rays and sea turtles, accounted for over half of the total catch. Catch per unit effort (CPUE; number of individuals per 1,000 hooks) was higher with control hooks compared to appendage hooks for all species?? categories except rays; appendage hooks caught 52% fewer sea turtles and 23% fewer tunas and billfish than standard hooks, which represents a significant reduction in bycatch of endangered and other species. No differences were found in the AHL for sea turtles, suggesting use of the appendage may not incur additional advantages regarding turtles?? post-release survivorship. Despite lower catch rates for marketable species, such as sharks and mahimahi, use of the appendage resulted in dramatic reductions in catch rates of sea turtles. The results suggest that large scale adoption of hooks with a significantly wider hook dimension could be an effective conservation measure to maintain marine biodiversity while allowing for continued fishing.     

Adsorption of isoxaflutole degradates to aluminum and iron hydrous oxides

Isoxaflutole is a preemergence herbicide that has been marketed as a substitute for atrazine. It is rapidly transformed to a more stable and soluble diketonitrile degradate (DKN) after field application and can further degrade to a benzoic acid degradate (BA) within soil. However, no previous research has been conducted to investigate DKN and BA sorption to metal oxide minerals. The primary objective of this research was to elucidate the interactions of DKN and BA with synthetic hydrous aluminum and iron oxides (HAO and HFO, respectively) to understand how variably charged minerals may influence adsorption of these compounds in soil. The herbicide degradates did adsorb to HAO and HFO, and the data were well described by the Freundlich model (R2 > 0.91), with Nvalues ranging from 0.89 to 1.2. Adsorption isotherms and Kd values demonstrate that BA is adsorbed to HFO to a greater extent than other degradate-mineral combinations that were studied. The degree of hysteresis between adsorption/desorption isotherms was characterized as slight (hysteresis index values < 1.7), suggesting weak DKN and BA retention to HFO and HAO oxide surfaces. Degradate adsorption was observed to greatly diminish as suspension pH increased. Attenuated total reflectance-Fourier transform infrared spectra show no evidence that DKN or BA adsorb to mineral surfaces as inner-sphere complexes under hydrated conditions. Instead DKN and BA adsorb to positively charged metal oxide surfaces as outer-sphere or diffuse ion swarm complexes via electrostatic attraction. This research indicates that metal oxides may serve as important retardants for DKN and BA migration through acidic soils enriched with aluminum and iron oxides.     

Devils lake emergency outlet diversion conflict

The Devils Lake Emergency Outlet Diversion conflict is systematically studied from a strategic viewpoint using the Graph Model for Conflict Resolution in order to obtain insights about the resolution of this nagging international dispute. By modelling the conflict for the situation existing as of July 2005, just before the project began operation, the dispute is put into proper perspective and, subsequently, a stability analysis is carried out to obtain potential resolutions or equilibria. The results of a sensitivity analysis accurately predict the deal which actually took place when Canada and the American state of North Dakota reached a negotiated settlement. Finally, suggestions are put forward for improving the Boundary Waters Treaty of 1909 between Canada and the United States.